 If you liked MW |  ...then you might like Kami no Kodomo |
Yuki and God's Child protagonist are evil bastards capable of killing and raping without showing any emotion. These protagonists also share a hatred for society and while in MW we get the motivation for the MC's behavior, in God's Child the protagonist is just pure evil in the shape of a person. It's also worth noting they both engage in homosexual acts hence the Yaoi tags. Worry not, it's nothing that happens too often but they have interesting origins. Both stories revolve around these sadistic protagonists and all of the atrocities they commit. So if you're into stories with serial killers devoid of emotions as protagonists